Historically, localized cancer of the esophagus was managed by either surgery or radiation therapy alone. Recently, studies have found a substantial improvement in survival when chemotherapy is combined with radiation therapy either alone or as an induction regimen prior to surgery. It has been demonstrated in several clinical trials of chemo- radiation followed by surgery that approximately 30% of patients will have no tumor found in the esophageal resection specimen at the time of resection. Clearly, local control after chemo-radiation is improved with the addition of surgery when residual disease is present. However, there is little data (none of which is randomized) demonstrating an outcome advantage with the addition of surgery when patients have achieved a complete pathologic response to preoperative therapy. Further, resection of the esophagus with a pathologic complete response has no clear therapeutic benefit and is associated with considerable morbidity. Consequently, rather than subjecting all patients to a resection, a more logical approach is to further refine current prognostic and diagnostic techniques to allow for a more rational selection of patients at risk of having residual disease after induction chemo-radiation. In a correlative study, we plan to evaluate the utility of [18F]-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) imaging, both before and at the completion of the induction chemo-radiation to assess changes in the tumor uptake FDG. Recent improvements in PET imaging suggest that this tool is sensitive for identifying subclinical disease; either at the time of initial staging or to determine recurrent/persistent disease during and following therapy. Further, although PET holds great promise, it is currently an expensive modality. Consequently, defining the optimal time for its use in a patient's course is clinically important. We plan to correlate the PET findings with endoscopic ultrasound (EUS), and spiral CT imaging to pathologic findings from resected specimens.